Through the development of the stochastic medium theory for predicting the settlement of the surface ground due to construction of underground engineerings, analyze deformation mechanism of soils is based on the stochastic medium theory. By establish the mathematical model of soil unit, providing the calculate formulas of predicting the settlement of the surface ground and method for determining the relevant parameters. According to assumptions of the calculation course based on the stochastic medium theory, put forward assumptions about applying stochastic medium theory for guiding design and construction of incline-rectifying engineering, offer proposal for expanding this theory to be used to construction of underground engineerings.